I would like to make the M XL and so on cache in different folders, so "\media\k2\items\cache\M" for the med, and so on for the sizes. Running a watermark script but I only wanna put it on the Large images so the small (preview image) has no watermark.

I tried editing components\com_k2\models\item.php
were i found the cache kinda referenced as
"if (JFile::exists(JPATH_ROOT.DS.'media'.DS.'k2'.DS.'items'.DS.'cache'.DS.'XS'.DS.$filename.'_XS.jpg')"

I added the ".DS.'XS'" but I really have no clue how to do this.

Hi. It's not that easy. I recommend you to not change the location of the images. If you want to apply some processing to specific images ( using your own script ) you can get the desired file for each image size by looking at the filenames. The part after the last underscore is the size of the image.

I understand that the_M and so on is the Image size.

The script from here:
dolcepixel.com/how-to-watermark-all-your-uploaded-images/

it watermarks a folder, I wanna make like a Shutterstock kinda vibe. so the small is clear, but when you click on the image the one in the lightbox is watermarked.

This is an issue of the script. You need to look at the script code and see where it fails. Anotherway to add watermark is to develop a K2 plugin triggered on the "onK2AfterSave" event. The plugin will be able this way to add the watermark every time an item gets saved.

Thank you, will look into this.

Sorry i'm such a newbie to this all.

It's fine. That's why this forum is. You are welcome.